Carburetor control



NOV. 12, A1935. `D GREG@ CARBURETOR CONTROL Filed Sept. 24, 1951 2 f 4rff/ Patented Nov. l2, 1935 UNITED STATES PATENT oFFic-E CARBURETORCONTROL David Gregg, Caldwell, N. J., assigner, by mesne assignments, toEclipse Aviation Corporation,

East Orange, N. J., a corporation of New Jersey pplication September 24,1931, Serial No. 564,952v 16 Claims. (Cl. 261-39) This invention relatesto fuel mixing devices, and more particularly to a means for regulatingmixing chamber.

Another object of the invention is to provide a fuel control for acarburetor adapted for use in connection with a supercharger thatincreases the fuel flow as the supercharger pressure is increased.

Other objects of the invention will appear from the followingbdescription of a preferred embodipanying drawing, in which the ligure isa vertical cross section of a carburetor or fuel mixing deviceconstructed according to the invention and to which is connected asupercharger.

Referring to the drawing, lil is the supercharger casing enclosing animpeller ii and having an inlet i2 and a discharge opening i3. Thesupercharger is driven by means preferably is connected to the engine(not shown) M to the carburetor inlet it.

The above described connection of a supercharger with the carburetor iswell known but occasions some carburetor problems which are not presentwhen the carburetor takes its air supply at atmospheric pressure.carburetor shoulddeliver a constant weight ratio of air to fuel underall operative conditions.- ordinary carburetor is incapable of doingthis, but within the narrow limits usually encountered, no correction isused.

The use of a supercharger increases the pressure range and causes thecarburetor to deliver a noticeably incorrect mixture, which is due tothe fact that the amount of fuel is governed by the suction at the jet,and as liquid fuel is comparatively inexpansible and the air expandsunder decreased pressure, the ratio of fuel to air 1ncreases as thepressure decreases.

of shaft l la, which It is obvious that the 'I'he above diiiiculty ir.obviated in the present invention by the inclusion of a pressureresponsive or barometric device exposed to the mixing chamber pressurefor controlling the fuel orice, which includes anv expansible bellows I7sealed with a 5 predetermined internal pressure, preferably below 3 forexpanding the bellows when the surrounding pressure is decreased.

carburetors adapted for use in superchargers, l0

In the fuel chamber i9 is ordinarily subjected to' Venturi tube 2li.

In the illustrated embodiment, the pressure i'rom 15 the super-chargeris conducted to the fuel chamber by tube I 5v at some point above fuellevel, which is kept at a constant height by means of iioat 2i acting onthe levers 22 to close valve 23 at Athe predetermined level. The bellowsI7 is 20 moval oi' the cover 26, held in place by any desired means,such as screws 21. bellows i7 is preferably provided with a threaded 25extension -29, by which it may be bodily moved with respect to cover 2Bfor adjustment and thereafter locked in position by nut 3i. The lower ormovable end cross-passage 38, but if desired, passage 3'! may beeliminated and bellows l1 be so adjusted whereby controlled opening 36provides the sole communi# cation between the fuel chamber i9 and jet32. i 40 In the operation oi the device. assuming that the superchargeris delivering a supply of air to the inlet of the carburetor in thedirection o1' the arrows shown in the ligure, the pressure at the mixingchamber 39 is transmitted to the fuel 45 chamber |9'and is impressed onthe expansible bellows il. The relative position of valve 34 may f be soadjusted with respect to fuel orifice 36 that at any predeterminedpressure, valve 34 closes the 6G orifice and allows all fuel to bedelivered through the primary fuel orifice 31. At pressures in excess ofthe predetermined pressure, valve 34 will be raised by the collapse ofbellows il and an increased. amount of fuel supplied to jet 32 to com-55 derstood that the pensate for the increased weight of air passingthrough the Venturi tube 20.

An ordinary throttle valve Il has been lillustrated, but the inclusionof the valve does not affect the operation of the control, and the valvemay be eliminated if'desired and the regulation of the amount of fuelmixture controlled by any other desired means, such as speed control ofthe supercharger or by throttling the supercharger inlet I2.

While a preferred embodiment of the invention has been illustrated anddescribed, it 'is unshowing and description are illustrative only andthat the `invention is not regarded as limited to the form shown, orotherwise, except by the terms of the following claims.

What is claimed is:

l. In a fuel mixing device, a constant level fuel chamber, a mixingchamber, a fuel jet therein, a supercharger connected to the mixingchamber, means for impressing supercharger pressure on the fuel chambervat all times, and a barometric device within the fuel chamber andactuated by fuel chamber pressure adapted to control the fuel deliveredby the jet.

2. Ina fuel mixing device, a fuel chamber, a

mixing chamber, a fuel jet therein, a supercharger connected to themixing chamber, means for impressing supercharger pressure onthe fuelchamber at all times, and a sealed expansible member actuated by thefuel chamber pressure adapted to control the fuel delivered by the jet.

3. In a fuel mixing device, a fuel chamber, ,a mixing chamber, a fueljet therein, a supercharger connected thereto, means for impressingsupercharger pressure on the fuel chamber at all times, said chamberhaving an outlet orifice to the jet, an expansible sealed bellows havingone end secured to an interior wall of the` fuel chamber, and meanssecured to the movable end of the bellows adapted to control the fuelorifice.

4. In a fuel mixing device, a fuel chamber, a mixing chambena fuel jettherein, a supercharger connected thereto, means for impressingsupercharger pressure on the fuel chamber at all times, said chamberhaving an outlet orifice to thel jet, an expansible sealed bellowshaving one end secured to an interior wall of the fuel chamber, andmeans secured to the movable end of the bellows adapted to enlarge thefuel orifice as the pressure in the fuel chamber is increased.

5. In a fuel mixing device, a mixing chamber, a fuel jet therein, a fuelchamber having an outlet orice to the jet, a supercharger connected tothe mixing chamber, means forming a connection between the mixingchamber and fuel chamber at all times, a sealed expansible bellowsWithinV the fuel chamber, said bellows having a stem at one endprojecting through the chamber wall for adjustably securing the bellowsthereto, and means at the opposite end of the bellows adapted to controlthe orifice.

6. In a fuel mixing device, a fuel jet, a fuel mixing chamber having athrottle, a constant level fuel chamber, means forming two passagewaysfrom the fuel chamber to the jet, a sealed expansiblev member in thefuel chamber adapted to control one of said passageways, and means 'forconveying mixing chamber pressure to the fuel chamber from a pointanterior of throttle` to a point above the fuel level.

'7. In a fuel mixing device, a fuel jet, a fuel mixing chamber having athrottle, a constant level fuel chamber, means forming two passagewaysfrom the fuel chamber to the iet, a sealed expansible member in the fuelchamber adapted to control one of said passageways, and means forconveying mixing chamber pressure to the fuel chamber from a pointanterior of throttle to a point above the fuel level, said expansiblemem- 5 ber being wholly within the fuel chamber and supported by one ofthe chamber walls.

8. In combination with a carburetor for supplying a. fuel mixture to anengine, a supercharger, an auxiliary fuel conduit for the carburetor, adevice for controlling the flow of fuel through the auxiliary conduit,said device including an expansible member responsive to thedifferential between the supercharger pressure and a predeterminedabsolute pressure, and said device bel5 ing arranged to close theauxiliary conduit when the differential pressure reaches a predeterminedvalue.

9. In combination with a carburetor for supplying a fuel mixture to anengine, a supercharg- 20 er, an auxiliary fuel conduit for thecarburetor, a valve for said passage, an expansible device forcontrolling said valve, said device having interior and exteriorsurfaces one surface being exposed to the influence of superchargerpressure and the 25 other surfacebeing exposed to the influence of aVpredetermined absolute pressure.

' to air passage pressure for supplying fuel to the 40 the fuel chamberactuated by the air pressure in the passage anterior of the throttle forincreasing the fuel supplied by the jet as the air pressure in thepassage is increased, said means including a sealed expansible bel- 5lows having itsexternal surface exposed to the air passage pressure.

l2. In a fuel mixing device, a fuel jet, a mixing chamber having athrottle therein, a supercharger connected tothe chamber, and movablemeans 50 actuated by the static pressure between the supercharger andthrottle adapted to control the amount of fuel delivered by the jetwhereby the weight ratio of air to fuel is kept substantially constant,said means including a resilient expansible member having limitedexpansive movement and exerting sufficient expansive force to prevent achange in member dimensions until the pressure reaches a predeterminedvalue.

13. In a fuel mixing device, a fuel jet, a mix- 50 ing chamber having athrottle valve therein, a

jet and means supercharger connected to the chamber and a genoma 3 forincreasing the fuel new delivered by the iet le. xn e mei mixing device,e coutent level when the supercharger pressure lslncreased. fuelchamber, a mixing chamber, a fuel jet 15. In a fuel mixingr device, aconstant level therein for delivering fuel from said` fuel chami fuelchamber, a mixing chamber, a. fuel jet tl'iere-1 ber, a supercliargerconnected to thefuel chamber,

in for delivering fuel from said fuel chamber, a means for impressingsupercharger pressure on v supercharger connected to the fuel chamber,the fuel chamber at all times. a sealed expansible

